reversed direct-injection burner

in analytical flame spectroscopy
https://doi.org/10.1351/goldbook.R05374
A direct-injection burner combines the function of nebulizer and burner. Most commonly the oxidant is also used for aspirating and nebulizing the sample. However, when the fuel is used for this purpose, the term reversed direct-injection burner is applied.
Source:
Orange Book, 2nd ed., p. 166 (https://media.iupac.org/publications/analytical_compendium/)